Question

From my previous question : At the moment the train’s speed is 45 km/h,
what is the magnitude of the total accelera-
tion?
Answer in units of m/s2

Answer 1

First convert 45 km/hr

Answer 2

12.5 m/s

Answer 3

heres where` the r comes from?? v^2/r

Answer 4

.959

Answer 5

It doesn't matter what the speed is. The earlier prompt says "slows down at a constant rate" which means the train experiences constant acceleration.

Answer 6

which is?

Answer 7

can you explain this further.

Answer 8

You're right. I overlooked the circular part. \[a = {v^2 \over r}\]

Answer 9

But that is only the centripetal component, there is still the tangential. We are asked for the total magnitude. \[a = \sqrt{\left(v^2 \over 2 \right)^2 + a_t^2}\]where \(a_t\) is the acceleration value you found in the other question.